Preheat the oven to 425°F.
Cut the potatoes in quarters and place in a bowl with the olive oil, salt , pepper, garlic, and rosemary; toss until the potatoes are well coated.
Transfer the potatoes to a sheet pan and spread out into 1 layer.
Roast in the oven for 10 minutes, stir, and cook for another 15-20 minutes (or until the potatoes are browned and crisp).
Remove the potatoes from the oven, toss with parsley, season to taste, and serve hot.